Cellphone recycling kiosks that have popped up recently across San Diego are billed as a convenient way to dispose of old technology, but law enforcement officers say the cash-dispensing machines are also being used by crooks to fence stolen devices.

Called ecoATMs, the self-service stations are in 12 shopping centers throughout the county, including all the major malls, said company spokesman Ryan Kuder. Consumers can use them to recycle phones of all types — as well iPads and other electronics — and get as much as $300 in return, Kuder said.

The San Diego-based company started in 2008 with the idea to give people an environmentally responsible way to dispose of old electronics and at the same time provide them the motivation to actually go ahead and do it, Kuder said.

The concept has turned out to be appealing to consumers, who have turned in hundreds of thousands of phones over the last few years, said Kuder.

But according to local law enforcement, the machines are also proving to be attractive to crooks.

In El Cajon, six cellphones were reported stolen in the first six weeks of this year in a series of thefts, Arvan said. Two teens, ages 14 and 15, were arrested in February in connection with the crimes.

Arvan said the teens would ask victims if they could use their phones to call one of their parents and then just run away with it. The boy and girl told investigators they used the recycle kiosks to get cash for the loot, Arvan said.

In San Diego between January 2011 and March of this year, about 270 cell phones were stolen in street robberies alone, said San Diego police Capt. Andy Mills. In many of those cases, a smartphone was the main target.

“I am seeing an increase in phones being the subject of the attack,” Mills said.

The devices, which become more technologically advanced as well as more expensive, have become this era’s “hot property,” he said.

And while police say there are a number of ways to fence stolen items — through online sites like Craigslist, the mail, swap meets or at unscrupulous stores where no questions are asked — some of them are ending up in ecoATMs.

“We are finding phones in there that are stolen,” Mills said.

Suzi Woodruff Lacey, a spokeswoman for the Salvation Army, was one of those who found her stolen iPhone 4 inside an ecoATM at Westfield Parkway mall in El Cajon last October.

It was taken by a woman pretending to help her as she shopped at a store in Mission Valley.

Lacey used the “Find my iPhone” app to track her device to the El Cajon mall and found it inside an ecoATM on top of a pile of other phones.

The company told her that the seller received $110 for it.

But potential phone sellers just can’t drop electronics into a slot and get cash.